Process of distilling with aluminum chloride



March 23,1926. 1,578,050

A. M D. MQAFEE PROCESS OF DISTILLING WITH ALUMINUM CHLORIDE Filed Jan. 20. 1922 7'0 F/A/JL CONDENSER Y Q Q I u 'Afo Patented Mar. 23, 1926.

UNITED STATES ALMER McDUFFIE mares, or PORT ARTHUR,

TEXAS, ASSIGNOR T0 GULF REFINING COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF TEXAS.

PROCESS OF DISTILLING WITH ALUMINUM CHLORIDE.

Application filed January 20, 1922. Serial nd..s3o,5s1..

To all whom. it army concern:

Be it known that I, ALMER MCDUFFIE MGAFEE, a citizen of the United States, residing at Port Arthur, in the county of J efferson and State of Texas, have invented certain new and useful Improvements in Processes of Distilling with Aluminum Chloride, of which the following is a specification.

This invention relates to processes of distilling with aluminum chloride; and it comprises a method of conserving heat and increasing the capacity of stills in the. distillation of oils with aluminum chloride to produce oils of lowered boiling point wherein the vapors coming from the stills prior to sending to a final condenser, are partially cooled to condense volatilized aluminum chloride and a certain amount of oil, the condensed aluminum chloride being returned to the still and the co-condensed oil being separated and recovered; all as more fully hereinafter set forth and as claimed.

In a current *method of producing oils of lower boiling oint from high boiling oils such as gas oi the high boiling oil is distilled in the presence of a small amount of anhydrous aluminum chloride; usually about 5 per cent. The aluminum chloride combines with or melts down in a small portion of the oil to form a heavy liquid which is kept stirred up through the rest of the oil by vigorous agitating means. Presuming gas oil boiling at, say, 600, is used, the mixture in the still enters into vigorous ebullition at about 500 to 550 F., the particular temperature depending upon the amount of aluminum chloride, the age of the charge, etc. The vapors evolved contain gasoline, kerosene and more or less volatilized aluminum chlo ride-or its compounds with hydrocarbons. In order to keep the aluminum chloride in the still and prevent its passing forward into the final condenser it is necessary to cool the evolved vapors somewhat. In the usual practice the condensate obtained in this partial cooling is refluxed back to the still. The uncondensed vapors are sent forward to the final condenser at a temperature of 300-350 F, generally not substantially above 350 F. They furnish gasoline or a mixture of gasoline and kerosene as the case may be; this depending upon the particular temperature at which they ,ingthe described are sent forward from the partial condensing means.

While the temperature required for this distillation is not great, being, as stated, about 500 to 550 F. with gas oil, a considerable amount of heat is required. The operation may be looked upon as one in which the gas oil is in all cases where volatization is involved the amount of heat required is comparative ly great. In so far as cooling takes place in the backtrapping or partial condensing means the heat requirements of the still are increased. I

It is the object of the present invention to lessen this heat requirement and to increase the capacity of the still. The from the boiling bath contain in addition to the gasoline some unchanged gas oil, aluminum' chloride and kerosene and the like. The oil condensed with the alumin'um chloride in the backtrapping means is mostly higher boiling oil than gasoline, such as kerosene. In the usual practice this condensate is-returned with the aluminum chloride to undergo distillation again. This adds to the heat requirements of the still. And as the condensate is a material of greater value than the gas oil it is economically better not to return such oils formed in the distillation. Such being the case, in the present invention I modify the usual procedure by not returning to the still the oils condensed with the aluminum chloride in the reflux or backtrapping means. If given opportunity, the aluminum chloride condensed in the backtrap separates gradually from the co-condensed oil and the two may be withdrawn separately. This I do, retu rning the aluminum chloride and abstracting the kerosene or kerosene containing oil.

In the described operation it will be noted that all the products of the action of aluminum. chloride on the gas oil are withdrawn from the still; there is no return of volatilized oils formed, such as. kerosene. The output of the still is therefore greater and the heat supplied to it is better utilized.

In the accompanyi g illustration I have shown, more or less diagrammatically, certain apparatus adapted for use in performprocess. In this showing element 1 is a suitable still set in furnace chamber 2 and provided with stirr ng means vapors evolved,

distilled as gasoline; and as 3. Oil may be added through inlet 4. Aluminum chloride may be added with the oil through this inlet or separately through manhole Outlet 6 is provided for emptying the still. Stirring means 7 are provided for agitating the contents of the still. The vapors produced in the still leave through outlet 8 leading to air cooled condenser 9. As shown, this air cooled condenser is provided with an outlet 10 at the bottom leading back to the still and with outlet 11 at a point somewhere above the bottom, this latter outlet being for the purpose of removing kerosene or oils containing kerosene. Vapors not condensed in this partial condenser pass forward past thermometer 12 into the vapor outlet 13 leading to a suitable condenser not shown. In the operation of this apparatus, presuming gas 011 to'be the material treated the gas 011 is dis tilled in still 1 which is charged through inlet 4. Agitator 7 keeps the aluminum chloride in suspension through the gas oil. The vapors passing through 8 carry kerosene and aluminum chloride which are condensed in 9 by the cooling action of the air,

and accumulate .in its bottom, the aluminum chloride underlying the kerosene. The aluminum chloride is tapped back into the still through valved pipe 10 while kerosene or kerosene containing oils are removed from time to time through 11. Kerosene obtained in 9 is a clean saturated product needing but little refining. It may be treated with a small amount of sulfuric acid to remove any adhering aluminum chloride and redistilled or otherwise treated.

What I claim is p 1. In the lowering of the boiling point of petroleum oils by distilling the same in the presence of aluminum chloride, the process which comprises partially cooling the vapors to condense out aluminum chloride and kerosene, separately condensing and collecting vapors of petroleum oils having boiling points below that of kerosene, separating the aluminum chloride from the kerosene by] settling, simultaneously returning the aluminum chloride to the still and-separately removing the collected kerosene.

2. The process of converting higher boiling hydrocarbons into lower boiling hydrocarbons which comprises distilling the same in the presence of aluminum chloride, passing the vapors of the distillation containing some of the aluminum chloride to a condenser, only partially condensing the condensable vapors of said vapors of distillation and condensing the'aluminum chloride, allowing aiuminum chloride to settle under the condensed vapors, simultaneously returning the aluminum chloride to the higher boiling oil undergoing distillation, andremoving thecondensed vapors from such condenser.

the condensed vapors. simultaneously re,-'

turning the aluminum chloride to the higher bollmg oil undergoing distillation and re- .moving the condensed vapors from such condenser, and treating the condensate to eliminate any remaining aluminum chloride.

4. The process of converting higher boiling hydrocarbons into lower boiling hydrocarbons which comprises distilling the same in the presence of aluminum chloride, passing the vapors of the distillation containing some of the aluminum chloride to a condenser. only partially condensing the condensable vapors of said vapors of distillation and condensing the aluminum chloride,

allowing aluminum chloride to settle under the condensed vapors, simultaneously returning the aluminum chloride to the higher boiling oil undergoing distillation and removing" the condensed vapors from such condenser and redistilling the condensate.

5. In the distillation of higher boiling hydrocarbons in the presence of aluminum chloride, the process which comprises passing the vapors of such distillation to cooling means, maintaining the temperature of the vapors in the cooling means at such a point that only a portion of the condensable vapors and all of the aluminum chloride carried to the cooling means will condense, while the remaining vapors will pass forward from such condenser, settling condensed aluminum chloride out of the vapors condensed in such condenser, simultaneously returning settled aluminum chloride to the higher boiling hydrocarbon undergoing distillation, and removing the condensed oils from such cooling means for subsequent treatment, and condensing the vapors leaving the said first cooling means.

6. In the distillation of higher boiling hy drocarbons in the presence of aluminum chloride the process which comprises passing vapors resulting from the distillation to cooling means, maintaining such cooling means at such a temperature that condensable relatively low boiling hydrocarbons will pass therefrom in the vapor state, while hydrocarbons having a boiling point intermediate the initial hydrocarbon used for distillation and the vapors passing from the cooling means are condensed 'insuch cooling means together with aluminum chloride accompanying the distilled vapors, separating therein the said intermediate condensed oil from the condensed aluminum ride, while permitting condensable hydrochloride and returning the condensed alucarbons having boiling points lower than minum chloride to the still. kerosene to pass from said cooling means 7. In aluminum chloride distillation of in vapor form, separating the aluminum petroleum hydrocarbons having boiling chloride from the condensed hydrocarbons points higher than kerosene, the process in said cooling means, simultaneously re- 20 which comprises passing vapors of such disturning said aluminum chloride to the bodytillation containing hydrocarbons having of higher boiling oil undergoing distillationv boiling points around that of kerosene and and removing the condensed oils from said lower boiling hydrocarbons, to cooling cooling means, and finally condensing vapors means, maintaining the cooling means at passing from said cooling means. I 25 such a temperature as to condense hydro- In testimony whereof, I have. hereunto carbons having boiling points around that 'aflixed my signature.

of kerosene together with aluminum chlov ALMER MoDUFFIE MCAFEE. 

